Piston-ring.



, E. NORWOGD.

PISTON BENQ. APPLzIcATIoH min was 21. 1917.

Meme-l Dee. l?, 1918.

ed tiene ,nel

Replication .filed June 2li 1913".

To all Miom, if may] nonne/rez.'

Be it known that I, JOHN E. onn'oon, a citizen of the United States? reiding at Baltimore, State of Maryland, have invented certain new and nsetul improvements in Piston-Rings; and do hereby lzee-lare the following to be a fnlh clean and exact. de seription of' the inventiom such will enable others skilled in the art- 'to Whieh i'. appertains to make and use the same.

rlhis invention relates to paelrings for pis# tons and While it is designed primarily for use in connection with explosive enginei, il; will be understood that it may he used in connection with any mechanism Vin which fr. piston is to be tted within a cylinder.

As is Well known, the piston an explosive engine is provided with any desired nun'iber or' eireumserihing grooves ineaeh of `vvhieh is disposed an open expansiilv'ring.-

Itis found in practice that in the use. of the ordinary ring, there is a loss of eo1npression by reason of the gas escape not only through the jointvof the ring ends 'ont also through the groove of the piston along.

the sides and under the ring. lit 'therefore highly important that not only shall the ring snugly tit with its outer periphery against the inner wall of the cylinder, end that the ends of the ring' he in elose, gaseieluding Contact, but also that the ring transversely lit the piston groove so as to be in gas-excluding Contact 'with both side walls of the latter.

It is the object ofthe present invention to form a ring which may be litted not only to the cylinder, but. also to the. piston groove so as to titthe latter transvers ly and lil ewise to provide a ring in which leakage throngrh the jointv of the endsq will be prevented.

Figure 1 is a. sertion taken longitudinally through a portion of the cylinder o?. an explosive engine having' therein a piston provided with rings` all embodying` the present invenlioin the piston and rings beine shown partly in serl'ion and partlyin elevatitna.

Fie'. L), is :i perspertive view showing the vomposite ring vut in two n'in its; resultant pnl-ts` in different planes.

Fieri, 3 a section on line il oi' hilf. hut with the perteA positioned' to voi lio llifj, l.

hier i is :i ser-tion on line Litpeeieaton of Letters atent.

Patented Der. t?, 1918. 3e-nei 176,177,

a portion ol the cylinder 5 ol an explosive engine in ivliieh is disposed a piston (i hav ing the usual cross-section: lly rectangular enmnnserilling,- grooveA T to receive each a pte-king ring.

The packing' ringemployed by me is a composite ring in that it includes two annular i nliers S and ll.

The annular member ti, as illustrated, is when in ustnot' greater exterior diameter than the member 9 and has also a greater general width, the latter dimension being very nearlyY the width of the piston groove 7.

The member 8 is beveled from one of its side t'aees l0 to its inner periphery 1l to form the under-ent tace l2 and itsy ends are provided with a lap joint t3.

The member l) beveled from its outer periphery l-l to its side 'l5 to 'forn the slanting' faee lo and the member 9 is disposed with ite. beveled portion within the ine'losure or" the member so that. its slanting l'aee 16 ',oiraets continuously with the undercut face lf2- of the member 8. The cylindrical portion of the outer periphery of the member il, n'hi is the nnheveled portion, has only a very relient lrnnsverse extension and projects ordv slightly troni the side, face 10 of the mer i i and heingzy in spaced relation inivardt ot' the outer periphery of the member ll, it loi-ms a shelf for a purpose to be, presently explained. lt, will be further noted that the outer diameter of the member l) is lees than 'the outer diameter ot' the piston G 'for a purpose that. will also loe presently explained. l

To prevent angular movement of the members i and 2l with resiieet. to each other, the member at its lap joint. i3 is transversely vhanneled in its inner peripher-7 as shown ist, ti, and projecting laterally from the ede-e o't' the member 9 is a eorrespondingjly respomling portion oi' the lap joint. ll and 'i eonnevti'on with the adiaeent portion of le member El completely rovers the line of le lop joint at the inner periphery ot' the on .i ier 8. thus priventine.` leakage through the lap joint :'a l`...ly oi' the member 8.

entire, the normal exterior dinnn ter ol' ze memlier il is greater than the major internal diameter oiI the member il. and when embers are nssen'ihled and 'oove ol the piston. the memnl and slide with its slzmting "wie onderuit, Vl'nerot' the member 8 lit-Se lil) lll() until it has` had a lateral movement eullicient to Contact with the corresponding face of the groove and force the member S against the opposite aee ot' the 1groove. As the member S wears on the cylinder Wall or the lat-ter wears and the member 8 expands, ra dially, a correspoiuling expansion of the member 9 is permitted. As wear occurs between the ring members and the side walls of the piston'I groove, there is further lateral movement of the members with respect to each other, to compensate, as will be understood.

Thus not only is there provided a riiig that automatically adjusts itself to tit the iston groove, but also the periphery of 'the vinner member forms -an oil Shell which receives and holds a body of oil in the don/nb Ward movement of the piston as the oil is scraped from the cylinder wall, insuring propel' lubrication between the member 8 and the cylinder, the positionin; of this shell' below the surface oi' the piston resulting in a poekete'd shell which insures a body ofoil in auch position as to oil-pack the contacting 'faces of the men'ibers S and 9 with a resultant eliiciene-y in the prevention of gas leakage therebetween. lt will be further meer@ noted that while the extension 18 covers the lap joint ot' the member 8, the under-out portion ot `the member S covers the lap jint of the member 9 excepting at the nnbeveled portion olf the periphery of the member 9, where the oil on the shelf etl'ec'tively pre vents leakage.

What is claimed is:

A composite piston ring comprising an outer meniber haring` jointed ends and a portion of itsl inner face beveled from one side to its inner periphery, an inner member having jointed ends and beveled Jfrom a Side face to its outer periphery, the members being; disposed with the alanting fafe resultant from their beweis in mutual Sliding' eontart and with the outer member Covering the joints of the ends of the eorrespondingportion ot' the inner member, the inner member` having a lateral extension Covering the con responding' portions of the joints of theends et the outer member.

.ln testimony whereof, I aliiX my signature in the presence of two witnesses.

JGHN E. NORW'OOD. lilitnesses Lewis H. MILLER, WILLIAM l. SCHUL. 

